Should you still worry about Japanese Knotweed in the winter?

Japanese knotweed can be a real menace. It grows rapidly and is very difficult to eradicate. In the UK, it has the label of an invasive species. It has been known to damage buildings, suppress plants’ development around it, and knock thousands off property prices.

The spread of Fallopia japonica (its Latin name) has reached epic proportions. It can now be found in many parts of London, Merseyside, Bristol, and Lancashire, and is spreading along corridors from Nottingham to Sheffield and Swansea to Newport.

Japanese knotweed grows most rapidly during the summer months, but that doesn’t mean it’s not a problem at other times of the year.

What Happens to Japanese Knotweed in Winter?

As temperatures start to plummet, Japanese knotweed looks like it’s dying off. The vigorously growing bamboo-like canes turn brown and look like they have no life in them. Don’t be fooled by its brown, brittle state. It remains very much alive and is just lying in wait for the spring when it will emerge bigger and stronger with fresh new shoots. The first signs of life will be red or purple shoots that look very much like asparagus.

What Are Your Responsibilities With Regards to Japanese Knotweed in Your Garden?

Japanese knotweed is included as an invasive non-native plant in an amendment to the Anti-Social Behaviour, Crime, and Policing Act 2014 and Wildlife and Countryside Act 1981 section 114 (2) (WCA 1981) While it’s not illegal to have knotweed in your garden, you are not allowed to let it have a “detrimental effect of a persistent or continuing nature on the quality of life of those in the locality.”

If you allow it to spread into neighbouring properties or land, you could face prosecution. It’s also worth remembering that it is classed as ‘controlled waste’ under the Environmental Protection Act 1990. This means you have to dispose of it responsibly by taking it to a licensed landfill site.

The best course of action is to hire a specialist Japanese knotweed contractor. They will be licensed to remove the weed from the site safely. Here at Japanese Knotweed Specialists, we can provide a site-specific management plan that will allow us to tackle Japanese knotweed in winter and any other time of the year. We also offer our customers an insurance backed guarantee as well.

Japanese Knotweed Problems Don’t Disappear Just Because It’s Winter

During the autumn, knotweed leaves start to turn yellow and fall to the ground. The stems of the plant will redden in colour, turning almost crimson. When winter hits, the leaves fall, and the shoots die back. All that’s left will be dead, straw-coloured, hollow stalks.

Just because you can’t see the Japanese knotweed doesn’t mean it’s disappeared, never to rear its ugly head again. On the contrary, the extensive rhizome root system will be very much alive.

Winter is one of the best times to knock the problem on the head for good. There is no above-ground vegetation to contend with. The brittle stems can be cut down efficiently and disposed of responsibly.

Care has to be taken because there is a risk of breaking off part of the crown attached to the network of rhizomes underground. If this happens, it can trigger new growth and lead to new knotweed areas appearing in the location. Ideally, the stems should be cut at least 10 centimetres above the crown of the knotweed stem.

Burning is another option, depending on local by-laws. If this method is used, you must scrape up all material and deposit it back onto the area. When removing Japanese knotweed, take care to clean your boots and tools when you’ve finished. This is to make sure you’re not transporting any fragments across your garden.

The Most Effective Way to Remove Japanese Knotweed in the Winter

Once that is done, it’s time to tackle the root system itself, which is the powerhouse of this invasive weed. Herbicides can’t be used in the winter because the plant must be in leaf. The solution in the winter is to dig-out the affected area. The soil has to be correctly handled and disposed of because the smallest of rhizome fragments can produce a new plant. Research has shown that a fragment weighing as little as 0.7g can lead to new growth.

A professional Japanese knotweed removal company like ourselves will be able to dig the crowns and rhizome network out. It is by far the most effective option for removing the risk of knotweed affecting a property. A large amount of waste will be produced, but it the preferred method for landowners who want to return their land to a knotweed-free state as quickly as possible.

For more information on Japanese knotweed removal, please don’t hesitate to contact us at any time of the year.